As is well known in the art, studies show that about 62% of power outages in North America are weather related and 22% are caused by utility equipment failure. In addition to cost due to power and equipment failures, the price of producing electricity increases every year. Smart meters are now in place in order to monitor usage at any moment of time and pass the higher price of electricity during high demand times to consumers. Therefore end users, e.g. residential homes and businesses, are looking for solutions that could provide them with a reliable (uninterrupted) electric power and at lower prices. Availability of the small-scale Distributed Energy Resources (DER) and Energy Storage Systems (ESS) for home applications has introduced a new concept of Smart Home where the consumers can easily be able to make intelligent energy choices of their interest. For example, the U.S. Pat. No. 4,644,320 and patent application 2003/0050737 disclose home energy control systems to minimize the cost of energy in a smart home application.
A common practice to supply power to a home in case of a utility failure is using a Backup Generator (BG). To transfer home loads to a BG, two main technologies currently exist: 1—using a high capacity transfer switch at the main entrance; and 2—using several low capacity transfer switches that connect some essential loads to the BG. In the first approach, all the home loads are supplied by a high capacity backup generator. The size of the BG, in this approach, must be the same size of the total loads of the home. In the second approach, only a small size generator is used to supply some essential loads only, at the user's discretion. As an example, the U.S. Pat. No. 8,766,489 provides a solution based on using a transfer switch to connect backup generators to supply power to home loads in case of a utility outage.
The existing transfer switches are mostly mechanical. They may be operated either manually or automatically. The minimum transfer time between the utility and BG is typically about 1 minute. Therefore, there is always a disruption. Also, none of the existing technologies can accommodate automatic switching between different energy sources in a seamless manner.
The present invention provides a solution for the abovementioned shortcomings. Intelligent transfer switching can maintain continuous supply of energy to a building from various sources of energy. In this approach, one or more of backup generators, energy storage systems and distributed energy resources (e.g. solar and wind) may be available to an end user, in addition to the main power utility. Furthermore, an intelligent power management system may be utilized to balance supply of power between the main utility and other energy sources in accordance with price of electricity in real-time in order to minimize consumption costs.